The present invention relates to a new and improved tree harvesting machine attachable to a vehicle, and more particularly, to an improved partial chain delimber in such a tree harvesting machine.
The present invention concerns a tree harvesting machine with a delimber assembly as generally shown and described in Moser et al. U.S. Pat. No. 3,842,872 entitled "Delimber Assembly for Tree Harvesting Machines", issued Oct. 22, 1974 . Other tree processing units of the tree harvesting machine to which the present invention has particular application are more completely described in Moser et al. U.S. Pat. No. 3,731,720 entitled "Shear Assembly for Tree Harvesters", issued May 8, 1973, and Gutman et al. U.S. Pat. No. 3,669,161 entitled "Drive Mechanism for Tree Harvesters", issued June 13, 1972. All of the above are assigned to the assignee of the present invention.
A tree is rarely, if ever, perfectly formed. The trunk of a tree is usually bent, crooked, curved or misshapen.
The prior art tree harvesting machines mentioned above are very effective in cutting and delimbing most trees. However, a tree which is curved or misshapen does present additional difficulties during the tree harvesting process, particularly when the tree is being delimbed. It is highly desirable for efficient tree harvesting that limbs and other protrusions be removed as completely as possible from trees to provide logs which can be easily handled during further processing. The flexible blade delimber of the harvesting machine shown in U.S. Pat. No. 3,842,872 provided accommodation for the changing size of a tree and to some extent its shape, but badly misshapen trees induced the failure of the flexible blade delimber to sever limbs as near the tree trunk surface as possible, especially in instances where the tree was bent, curved, or partially concave such that the delimber blade could not follow such bends or curves.